--
I think I remember that in the 1940's, a linguist (may have actually
been Whorf?) concluded that the longest English syllable in terms of
sounds (phonemes) -- not letters -- was "thou triumphedst" (presumably
based on a pronunciation of it as [traimpftst?). Of course, this
involves some cheating (relying on fast speech coalescence of two
syllables into one, using archaic 1600's ending, etc.), but it's cute
in its way...